2. The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $4.31 to $4.555. The reporting persons undertake to provide to the issuer, any security holder of the issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

4. Index Venture Associates III Ltd. ("Index III GP") is the general partner of the Index III Funds, Index Venture Associates IV Ltd. ("Index IV GP") is the general partner of the Index IV Funds and Index Venture Associates V Ltd. ("Index V GP") is the general partner of the Index V Funds. Yucca (Jersey) SLP is the Administrator of the Index Co-Investment Scheme acting through Intertrust Employee Benefit Services Limited. Each of Index III GP, Index IV GP and Index V GP disclaims Section 16 beneficial ownership of the securities held by the Index III Funds, Index IV Funds and Index V Funds, respectively, and the shares held by Yucca Jersey, except to the extent of its respective pecuniary interest therein, if any, and this report shall not be deemed an admission that Index III GP, Index IV GP or Index V GP is the beneficial owner of such securities for Section 16 or any other purpose.

6. The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $4.25 to $4.60. The reporting persons undertake to provide to the issuer, any security holder of the issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.